Guitar chords in the key of G:
Chord Gdim7 v.2 notes: Bb, E, G, Db and E. You should not play the 6th string.
The guitar strings 3(G) and 1(E) are left open.
Gdim7 - G diminished seventh guitar chord's alternative names: G°, G°7, Go7, G7dim. See also: Gdim and Gm7b5.
Steps: 1-b3-b5-6(or bb7).
1(G), b3(A#/Bb), b5(C#/Db), 6(E).